freebsd-update upgrade problem

[Manolis Kiagias]

Hi,

I have already upgraded a couple of machines from 7.0-RC1/2 to 
7.0-RELEASE using:

freebsd-update -r 7.0-RELEASE upgrade

However, on this one machine, I get this:

freebsd-update: cannot open files/.gz: No such file or directory

I checked free space on the root partition, no problem there. I also 
deleted and recreated /var/db/freebsd-update, to no avail.
I am quite baffled, the machine is more or less the same with the ones 
that upgraded without a hitch. I googled for this and found essentially 
nothing - two people having the same problem, but no answers.

Any ideas?